Non-Monitored Circuits

the pcm does not monitor the following circuits, systems, and conditions even though they could have malfunctions that result in driveability problems. A diagnostic code may not be displayed for the following conditions. However, problems with these systems may cause a diagnostic code to be displayed for other systems. For example, a fuel pressure problem will not register a diagnostic code directily, but could cause a rich or lean condition. This could cause an oxygen sensro, fuel system, or misfire monitor trouble code to be stored in the PCM.

Engine Timing -  The PCM cannot detect an incorrectly indexed timing chain, camshaft sprocket, or crankshaft sprocket. The PCM also cannot detect an incorrectly indexed distributor or Cam Sensor. (*)

Fuel Pressure -  Fuel pressure is controlled by the fuel pressure regulator. The PCM cannot detect a clogged fuel pump inlet filter, clogged in-line filter, or a pinched fuel supply. (*)

Fuel Injectors -  The PCM cannot detect a clogged fuel injector, a sticking pintle, or that an incorrect injector is installed. (*)

Fuel Requirements -  Poor quality gasoline can cause problems such as hard starting, stalling, and stumble. Use of methanol- gasoline blends may result in starting and driveability problems. (See individual symptoms and their definitions)

PCM Grounds -  The PCM cannot detect a poor system ground. However, a diagnostic trounle code may be stored in the PCM as a result of this condition.

Throttle Body Air Flow -  The PCM cannot detect a clogged or restricted air cleaner inlet or filter element. (*)

Exhaust System -  The PCM cannot detect a plugged, restricted, or leaking exhaust system. (*)

Cylinder Compression -  The PCM cannot detect uneven, low, or high engine cylinder compression. (*)

Excessive Oil Consumption -  Although the PCM monitors the exhaust oxygen content through the oxygen sensor when the system is in a closed loop, it cannot determine excessive oil consumption.